16 lines
453 B
Text
16 lines
453 B
Text
{-|
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Returns `True` if the supplied function returns `True` for a present element and
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`False` otherwise
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-}
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let any
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: ∀(a : Type) → (a → Bool) → Optional a → Bool
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= λ(a : Type) →
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λ(f : a → Bool) →
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λ(xs : Optional a) →
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merge { Some = f, None = False } xs
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let example0 = assert : any Natural Natural/even (Some 2) ≡ True
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let example1 = assert : any Natural Natural/even (None Natural) ≡ False
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in any
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